Earth is being invaded by an alien race called mimics. Possessing high-tech weapons, uninvited guests first attack the largest cities, and completely destroy them. Humanity has no choice but to join forces to try to repel the alien invaders, but to do so is not easy. In battle throw all possible forces, both professional military and civilian, who do not have even the slightest idea about the conduct of the battle. One of them becomes and the most the usual guy named bill cage. He dies in the first battle, but before that he still manages to destroy one of the aliens, during the fight with whom bill falls into a time loop. As a result of the incident, he again and again experiences the last day of his life, which, in the end, brings him closer to the solution of how to defeat the alien invaders…